https://devzone.nordicsemi.com/f/nordic-q-a/10767/nrf52-systick-clock-sourceCan someone please provide detail on the clock source for the SysTick in the nRF52? Is it clocked by the processor clock or an additional clock source? I&#39;m trying to understand if it could be used when the processor is asleep?en-USTelligent Community 13Wed, 09 Dec 2015 20:24:50 GMThttps://devzone.nordicsemi.com/thread/40235?ContentTypeID=1Wed, 09 Dec 2015 20:24:50 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8ea06705-4387-40cd-bfd8-1b6fcdfae14fH&#229;kon Alseth<p>Hi Darren,</p> <p>There&#39;s a bit of info about the subject in this thread: <a href="https://devzone.nordicsemi.com/question/55805/systick-timer-on-nrf52-fires-15-as-often-as-expected/">devzone.nordicsemi.com/.../</a></p> <p>The SysTick is clocked from the cpu clock, and will only work when the CPU core is active (not in WFE/WFI).</p> <p>Cheers, Håkon</p><div style="clear:both;"></div>